Overloading in Python

Question

I have stumbled on one question in SoloLearn's quizzes. I know how overloading is working in Python and I understand how it changes built-ins. But I don't understand this code:

class wow:
def __init__(s,x):
s.x=x
def __add__(s,y):
return wow(s.x - x.y)
def __sub__(s,y):
return wow(s.x + x.y)
def __repr__(s):
return str(s.x)

a = wow(5)
b = wow(7)
c = wow(3)

OK. s = self. I know that only position is important, not it's name.
But how we use wow's __init_ in the overloading if 'y' is not defined? And what does this 'x.y' means? I thought we need to define 'y' before defining overloading.
Please, help to understand it.

Answer 1

First of all, you incorrectly copied the question.
in __add__ it should be y.x rather than x.y.
so + overloading works as below.
a+b is a.__add__(b). where a and b are both objects of the same type.
def __add__ (s,y): should be read as __add__(self,other)
return self. x - other.x
in other words it just overload + with -